Harley. Looking in an older Lyman reloading manual,(#43), they show the Colt N. P. and the 38 S&W as being the same cartridge. I think it was because they wanted their brand name on the gun, IE, 38 S&W on Smith's and 38 Colt N. P. on Colt's. If memory serves, this was done on the 38 Spl. for a time also.(38 S&W Spl vs 38 Colt SPL, the only difference being nose shape)
To my knowledge, ammo for the 38 S&W is still available.
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